JDK 16 RFR of JDK-8250246: Address reliance on default constructors in security libs

[Joe Darcy]

Hello,

Please review a set of changes to add explicit constructors to replace 
default (implicit) constructors in various classes in security libs 
across several modules:

     JDK-8250246: Address reliance on default constructors in security libs
     http://cr.openjdk.java.net/~darcy/8250246.0/
     CSR: https://bugs.openjdk.java.net/browse/JDK-8250248

(This is a companion to similar changes being made across other 
libraries in preparation for creating a new javac lint warning.)

One of the classes seems to only accidentally have a constructor, so I 
added that one as terminally deprecated.

Thanks,

-Joe